1. Field of the Invention
This invention relates to curable epoxy resins. More particularly, to a novel curing system, salicylic acid and MIBPA.
2. Prior Art
Epoxy resins constitute a broad class of polymeric materials having a wide range of physical characteristics. The resins are characterized by epoxide groups which are cured by reaction with certain catalysts or curing agents to provide cured epoxy resin compositions with certain desirable properties. Known curing agents are anhydrides and amines. Salicylic acid is known as an accelerator for epoxy resins but not as a co-reactant as here. See Lee and Neville, Handbook of Epoxy Resins, p. 11-18 and U.S. Pat. No. 3,639,928.
Prior art epoxy resins are used as coatings, castings and sealants. An important growing application for epoxies is light weight body parts for machinery such as automobiles. This application requires an epoxy part which can withstand the high temperatures of a paint baking oven without undergoing noticeable distortion. Also structural strength is required. My invention is a novel curing system which imparts these properties to epoxies.